Known spoilers are disclosed in JP10-167126A and in JP3526021B.
A roof spoiler (a spoiler) disclosed in JP10-167126A, which is formed by injection molding, is provided along a rear edge of a roof panel (a roof). The roof spoiler is provided on the roof panel so as to cover hinge members that are mounted to the rear edge of the roof panel and are pivotally supporting a back door. The roof spoiler pivots about hinge shafts of the hinge members relative to the roof panel in response to a pivotal movement of the back door.
An air spoiler (a spoiler) disclosed in JP3526021B is made of thermoplastic resin by blow molding and is mounted to a rear hatch door (a back door) of a vehicle. The rear hatch door is pivotally mounted to a roof end of a roof panel (a roof) of a vehicle by means of hinges. The air spoiler pivots about hinge shafts relative to the roof panel in response to a pivotal movement of the rear hatch door.
According to each of the above-described known spoiler, a gap (a required clearance) is provided between the spoiler and the roof so as to allow the spoiler to pivot relative to the roof. From a viewpoint of appearance of the roof, the smaller required clearance is better. In order to reduce the required clearance, the hinge shafts need to be provided as close as possible to a design surface (an upper wall portion) of the spoiler. In particular, thickness of the spoiler needs to be reduced as much as possible at portions located above the hinge shafts.
The spoiler disclosed in JP10-167126A is injection molded and includes only one surface layer (an upper wall portion) that constitutes the design surface. Therefore, thickness of the spoiler at the portions located above the hinge shafts may be reduced relatively simply, however there arises a concern of heat deformation or decrease in strength of the portions. It is conceivable to constitute the design surface with two layers by injection molding the upper wall portion and the lower wall portion separately, and by adhesively joining them together. The constitution, however, requires additional cost and involves concerns of deterioration of appearance, strength and a waterproof performance of the joints.
Since the spoiler disclosed in JP3526021B is a hollow unit made by blow molding, in order to reduce thickness of the spoiler at the portions located above the hinge shafts, the upper wall portion and the lower wall portion need to be formed as close to each other as possible. When the upper wall portion and the lower wall portion are formed closer, the two walls adhere to each other after a blow molding process, and thus sink marks are more likely to occur on the design surface. The sink marks occurring on the design surface need to be eliminated in order to improve the appearance of the spoiler, which requires additional cost for surface finishing and so forth.
A need thus exists for a spoiler device which is not susceptible to the drawback mentioned above.